Laura scored a 1400 on her SAT. She wanted a higher score, so she took an SAT preparation course after school for six months. The class was so hard that she almost dropped out – but she kept going and the class got easier. She took the exam again last month and now has the envelope with the test score in her hand. She opens it and is thrilled when she sees an 1800.
Congratulations Laura. 1800-1400=400 So all she really did was receive 400 more points from the last exam.